The present invention relates to a sinker mechanism installed in a flat knitting machine of which front end rear needle beds are arranged to face each other with their distal ends.
A conventional mechanism of sinkers disposed to the front ends of the needle beds of the flat knitting machine is based on an assembly of a swingable sinker which serves as a yarn guide and a stationary loop forming plate having an edge for forming a loop of yarn. In action, the swingable sinker on each needle bed turns forward to close the distance between the two needle beds and to guide the yarn fed from a yarn feeder to a lower position. Because of the action of the sinker mechanism, the previously formed loop of the yarn held on a knitting needle can be prevented from slipping off when the knitting needle advances to catch the yarn with its hook to form a new loop.
Also, another conventional sinker mechanism permits each sinker to have a loop forming edge portion shaped of a substantially arcuate configuration and a yarn holding portion provided in front of the loop forming edge. In action, as the sinker swings forward, its yarn holding portion presses down the previously formed loop to a lower position beneath the front end of the needle bed so that the previously formed loop is prevented from slipping off.
The former of the two conventional sinker mechanisms has however a drawback that the sinker acts as a yarn guide and also, as a loop slip-off preventing member and thus, provides a reduced force in pressing down the previously formed loop. Particularly, during the forming of loose loops of yarn, it often happens that the previously formed loop is not released from the latch of a knitting needle.
The sinker of the latter certainly presses down the previously formed loop with its yarn holding portion preventing the production of double loops. However, the yarn to be fed to the hook of the next knitting needle is drawn from a yarn feeder over the loop forming edge of the sinker and thus, tends to be carried above the hook. As the result, the yarn fails to be caught by the hook of the knitting needle and will not be looped.